2021 Fiscal Year Annual Research Report
The semi-aquatic brains of seals, does the return to water lead to predictabl e anatomical changes?
| Project/Area Number |
21K06404
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| Research Institution | Hokkaido University |
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Principal Investigator |
PATZKE NINA 北海道大学, 高等教育推進機構, 助教 (20801690)
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| Project Period (FY) |
2021-04-01 – 2022-03-31
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| Keywords | evolution / brain / comparative neuroanatomy / carnivores / pinnipeds |
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| Outline of Annual Research Achievements |
In this project we aim to determine the strength of aquatic environment, on the evolution of the mammalian brain by investigating the semi-aquatic carnivores, the pinnipeds. We will determine whether the pinniped brain is more similar to the taxonomically related terrestrial carnivores or the environmentally related fully aquatic whales. We collected specimens of 5 spotted seals, 2 Steller sea lions, 4 bears and 2 racoons. All brains were scanned for structural analysis using a 3T MRI scanner. The data of hippocampal volume and brain volume has been processed and hippocampi of all 4 species have been subjected to immunohistochemistry. Our preliminary results demonstrate that pinnipeds have relative smaller hippocampi compared to terrestrial carnivores. Furthermore the semiaquatic pinnipeds have a reduced adult hippocampal neurogenesis. These results are in line with the findings we previously observed in whales.
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